1. Field
Embodiments of the present invention relate to a robot and a method for controlling the same, and more particularly to a robot, which has one control unit to control the overall operation of the robot and another control unit to supplement the function of the control unit, and a method of controlling the robot.
2. Description of the Related Art
In general, robots are machines, which conduct motion similar to that of a human. Initial robots were industrial robots, such as manipulators or transfer robots for the purpose of automation and unmanned operation of production. Recently, a robot, modeled on the biped walking of a human, has been researched and developed. The biped walking has disadvantages, such as instability and difficulty in pose control or walking control, compared with the quadruped or hexapod walking, but has advantages, such as more flexibly coping with an uneven surface of the ground (a rugged road) or a discontinuous walking surface (for example, stairs). In addition to such a biped robot, there are robots having various moving units, such as multi-legged robots having three legs or more and robots moving using wheels instead of feet.
The walking of a biped robot is carried out by the following process. The biped robot predetermines a walking direction, a step length, a walking speed, etc., and generates walking patterns of respective legs corresponding to the above predetermination to maintain the balance of the robot, and calculates walking trajectories of the respective legs according to the walking patterns. Further, the biped robot calculates positions of joints of the respective legs through inverse kinematics calculation of the calculated walking trajectories, and calculates target control values of motors of the respective joints based on current positions and target positions of the motors of the respective joints.
The biped walking is achieved through servo control to cause the respective legs to follow the calculated walking trajectories. Thus, it is detected whether or not the positions of the respective legs precisely follow the walking trajectories according to the walking pattern, and torques of the motors are adjusted such that the respective legs precisely follow the walking trajectories, when the respective legs are deviated from the walking trajectories.
A conventional robot includes a control unit to control the overall operation of the robot. When a software or hardware fault of the control unit occurs while the robot carries out a given instruction to perform a motion, the normal control of the robot may be impossible. The robot, which is not controlled normally, may be abnormally operated and thus destruct other peripheral structures or persons.